The present invention relates in general to safety belt retractors employed in vehicles for retaining passengers in their seats during emergency conditions and more particularly to a structural control means which synchronizes locking engagement of such a safety belt retractor.
In emergency locking retractors of the type typically used with vehicular safety belts, designed to prevent belt protraction under sudden inertial changes, such as collision or sudden stop, it is commonly known to utilize two locking ratchets or wheels on the belt winding spool in order to lock the spool and belt against emergency responsive protraction. The movement of a locking pawl into engagement with the associated locking ratchets has generally been controlled by the engagement of a programming pawl with a programming ratchet mounted to the same spool. The programming pawl may engage the programming ratchet in response to motion of a vehicle inertia sensor or strap acceleration responsive device and, is, thereafter moved by rotation of the programming ratchet due to further spool rotation. Such movement of the programming pawl may be used to actuate the locking pawl into engagement with the locking ratchets whereby further spool rotation and belt protraction is precluded. It is important to the reliability and durability of the retractor that the means for transferring the affect of the programming pawl and programming ratchet lockup to the locking pawl and locking ratchet lockup effect be of a reliable and durable nature.
It is the primary object of the present invention to disclose and provide a synchronized locking retractor of the foregoing type which is actuated into a belt retention mode by a structurally strong control means. More specifically, it is an object of the present invention to disclose and provide a rugged structurally strong control means for synchronizing the engagement of the programming pawl and programming ratchet with the locking pawl and locking ratchet once the programming pawl is engaged in response to an inertia sensor means. Synchronization is effectuated even when subject to great torsional and inertial load from the rotational shaft and the possible abusive loadings that can be generated under severe circumstances in a variety of applications. Further the embodiments reduce variations in synchronization due to component tolerance by minimizing components.